Sewing machine needle positioning means



Aug. 19, 1958 A. N. HALE. 2,847,956

SEWING MACHINE NEEDLE POSITIONING MEANS Original Filed Aug. 20, 1951 7Sheets-Sheet 1 g E E it 1 1% \H y E i Q INVENTOR. Ari/nu" Q l. gfqleWITNESS BY E A. N. HALE 2,847,956 szwmc MACHiNE NEEDLE POSITIONING MEANSoriginal Ema Aug 20. 1951 Aug, 19, 1958 v Sheets-Sheet 2 INVENTOR. @athur Vi. gfale WITNESS ATTORNEY Aug. 19, 1958 NQHAL 2,847,956

SEWING MACHINE NEEDLE POSITIONING MEANS Original Filed Aug. 20. 1951 7Shams-Sheet s QIQ G fig m {Lg Q k "7 1 IV? 5% J53 .;g I 2 r g i -J me iI I! g E T INVENTOR. q'rthm l L fale WITNESS BY W /ad ATTORNEY A. N.HALE v SEWING MACHINE NEEDLE POSITIONING MEANS Original Filed Aug. 20,1951 Aug, 19, 1958 7 Sheets-$heet 4.

Q4 m Q m E QM Tm. E a, & Q 1 u m 4 v I z I |r|| N Q? N 8 Wm Q km E m WNN INVENTIJR. @rt/zmrQZ rille WITNESS ATTORNEY Aug. 19, 1958 A. N. HALE2,847,956

SEWING MACHINE NEEDLE POSITIONING MEANS Original Filed Aug. 20, 1951 7Sheets-Sheet 5 ATTORNEY Aug. 19, 1958 A; N. HALE I 2,847,956

SEWING MACHINE NEEDLE POSITIONING MEANS Original Filed Aug. 20, 1951 I 7Sheets-Sheet 6 INVENTOR.

. ATTORNEY Aug. 19, 1958 I A. HALE SEWING MACHINE NEEDLE POSITIONINGMEANS 7 Sheets-Sheet 7 Original Filed Aug. 20, 1951 Y m 3 m 0 NW R m w mB, 0 8 NW T N I. n a v A n M m W S w, m m 6 1/ W Q \o\ 0 \E W Y A B 3 RZ 0 ,m. M m m m m S 55% w$b $35 6 8 MM w my T m W United States Patent2,847,956 SEWING MACHINE NEEDLE POSITIONING MEANS Arthur N. Hale, ParkRidge, 111., assignor to The Singer Manufacturing Company, Elizabeth, N.J., a corporation of New Jersey Continuation of application Serial No.242,715, August 20, 1951. This application June 9, 1955, Serial No.514,145

32 Claims. (Cl. 112219) This invention relates to sewing machines andmore particularly to a device for controlling the operation of themachines. This application is a continuation of my application SerialNo. 242,715, filed August 20, 1951, now abandoned.

An object of the invention is to provide a sewing machine with amechanism which will assure the stopping of the sewing needle in apredetermined position.

A further object of the invention is to provide a sewing machine with amechanism which will assure the stopping of the sewing needle in aselected one of a multiple number of predetermined positions.

Another object of the invention is to provide a sewing machine with amechanism which will assure the stopping of the sewing needle in aselected one of a multiple number of predetermined positions and toprovide a device, operable at desired intervals, to assure stopping ofthe sewing needle in another of the predetermined positions.

A still further object of the invention is to provide a torque-sensingcontrol mechanism for a sewing machine.

Another object of the invention is to provide an electric powertransmitter having a controlled braking action and a two speed drive.

Another object of the invention is to provide a braking mechanism for asewing machine which will absorb the kinetic energy of the moving partsin distinct steps.

In the drawings,

Fig. l is a front view in elevation of a sewing machine and transmitterembodying the invention.

Fig. 2 is a right end view in elevation of the sewing machine andtransmitter embodying the invention shown in Fig. 1.

Fig. 3 is a rear view in elevation of the sewing machine and transmitterembodying the invention shown in Fig. 1.

Fig. 4 is a left end view in elevation of the transmitter shown in Fig.1.

Fig. 5 is a front view of the transmitter showing the clutch and brakemechanism in section.

Fig. 6 is a partial right end view of the sewing machine showing thetimer cover-plate removed.

Fig. 7 is a left end view of the sewing machine head with the end plateremoved.

Fig. 8 is a partial sectional view of the balance wheel and timer takenon line 8-8 of Fig. 6.

Fig. 9 is a sectional view of the transmitter taken on line 9--9 of Fig.5.

Fig. 10 is a sectional view of the torque coupling taken on line 10--10of Fig. 5.

Fig. 11 is a partial sectional view of the control ring taken on line11-11 of Fig. 5.

Fig. 12 is a partial sectional view of the control stud taken on line12-12 of Fig. 11.

Fig. 13 is a schematic wiring diagram of the electrical control system.

Fig. 14 is a graphical representation of the time required to stop themachine from full speed.

Referring more specifically to the drawings, a sewing machine 10 ismounted on the usual supporting table 11 which also carries an electricpower transmitter 12. The sewing mechanism of the sewing machine may beof any conventional type, for example, such as that shownin U. S. PatentNo. 2,206,285, dated July 2, 1940. The sewing machine includes the usualbracket-arm 13 having a horizontal portion 14 terminating in a hollowhead 15. A needle-bar 16 is supported in the hollow head 15 forreciprocatory motion and is pivotally connected to one end of aconnecting link 17. The link 17 is pivotally connected to a crank 18fastened to one end of an actuating shaft 19 rotatably journaled in thesewing machine bracket-arm 13. Power is supplied to the actuating shaft19 from a driving pulley 20 driven through a belt 21 from a pulley 22.The pulley 20 is attached to a hub 23 which is secured to the shaft 19by a set screw 24.

The electric power transmitter 12 includes a frame 25 fastened to thebottom of the table 11 by bolts 26, nuts 27, and locknuts 28. A drivingmotor 29 is fastened to the frame 25 and carries a flywheel 30 fastenedto one end of the motor rotor shaft 31. One face of the flywheel isrecessed to receive a clutch facing 32 which is fastened to the flywheel30. A driven disc 33 is has tened to a driven shaft 34 which carries thedriven pulley 22. The driven shaft 34 is journaled in bearings 35 fittedin counterbores 36 in the operating sleeve 37. Helical ridges 38 areprovided on the outer surface of the sleeve 37 which operate incorresponding helical grooves 39 in the frame 25. An operating lever 40is fastened to the outer end of the sleeve 37 and is attached to theusual foot treadle (not shown) by a conventional treadle connecting rod41 and spring device 42.

A large diameter control gear or auxiliary driving gear 43 is journaledon the sleeve 37 and carries a clutch facing 44 of friction materialfastened to an axially extending drum portion 45 of the gear 43. A brakering 46 carrying a friction facing 47 surrounds the drum portion 45 andis pivotally mounted on pivot studs 48 carried by the equalizing ring48' which is in turn pivotally carried by the frame 25 on pins 48". Acontrol ring 49 surrounds the hub portion of the control gear 43 and isprovided with an internal ridge which engages a groove 50 in the controlgear hub. Rotary and axial motion of the control ring 49 is limited bypins 51 carried by the ring and positioned in curved cam slots 52 formedin a stationary ring 53 which is fastened to the frame 25. At anotherpoint on its periphery, the control ring 49 is provided with abifurcated stud 54 carrying a brake tail 55 and operating in a slot 52.A hole 56 is provided in the brake tail 55 to receive a plunger pin 57which is urged through a hole in the frame 25 into the hole 56 by aspring 56'. A control stud 58 fastened to the control ring passesthrough one of the curved slots 52 and is connected to the table 11 by aspring 59. The control stud is also connected to the foot treadle (notshown) by a spring 60 and rod 61. This mechanism provides a means forconnecting the control gear 43 to the disc 33 and also for rendering theconnection ineffective.

The transmitter rotor shaft 31 extends from the rear end of thetransmitter and carries a pulley 62. A countershaft 63 is rotatablyjournaled in a support arm 64 integral with the frame 25 and carries apulley 65 at one end and a gear 66 at the other end. Power istransmitted between the pulleys by a belt 67. A second countershaft 68is rotatably journaled in the support arm 64 and has a gear 69 fastenedthereto and meshing with the gear 66. A collar 70 fastened to thecountershaft 68 holds it in position. One end of a torque couplingsleeve 71 is fastened to the countershaft 68 by a set screw 72 while theother end rotatably receives one end of a control shaft 73. An opening74 in the coupling sleeve is covered by a plate 75 provided with ahelical slot 76 which receives a coupling pin 77 fastened to' thecontrol shaft 73. Relative rotation between the coupling sleeve 71 andthe control shaft 73 is resisted by a coil torque spring 78 which hasone end fastened to the coupling sleeve 71 and the other end fastened toa collar 78 attached to the control shaft 73. A gear 79 fastened to thecontrol shaft 73 meshes with the control gear 43. A bearing boss 80supports the control shaft 73 for both rotary and axial motion. The gear43 is driven from the rotor shaft 31 at a constant reduced speed.

A control switch 81 is mounted on the frame 25 with its operatingplunger 82 adjacent the end of the control shaft 73 to be operated byaxial movement of the shaft. This control switch in conjunction with thetorque coupling and shaft 73 forms a torque or power-flow sensingdevice. The control or torque switch 81 controls the flow of electriccurrent from one conductor 83 of a power supply line to a conductor 84connected to the contact assemblies 85 and 86 of a timer 87. The timer87 comprises an adjusting plate 88 mounted on a bearing 89 for angularadjustment with respect to a sewing machine balance wheel 90. The twocontact assemblies 85 and 86 are adjustably fastened to the plate 88 byscrews 91 and 92. The contact arms 93 and 94 of the contact assemblies,respectively, carry a follower finger 95 and 96, each of which is urgedinto contact with a cam 97 by a spring 98. The cam 97 is formed on theend of the hub 23 and is provided with a fiat portion 99. The contactassemblies 85 and 86 are adjusted to remain in the open position, shownin Fig. 6, until the follower finger of the contact assembly reaches theflat portion 99 of the cam 97, at which time the contacts 100 or 101will close, depending on which finger engages the flat portion 99. Adouble-pole double-throw selector switch 102 having contacts 103, 104,105 and 106 and switch blades 107 and 108 determines which one of thetimer contact assemblies 85, 86 normally controls the electric circuit.Two fixed contacts 109 and 110 of the selector relay are, respectively,connected to the blades 107 and 108 of the selector switch 102. Theremaining fixed contact 112 of the selector relay is connected to onefixed contact 113 of a primary relay 114. A movable double contact 115of the selector relay 111 is connected to one movable contact 116 of theprimary relay 114 and also to one terminal 117 of the primary relay coil118. Two movable contacts 119 and 120 of the primary relay are bothconnected to the power supply line conductor 83. A second fixed contact121 of the primary relay is connected to the conductor 84 at one side ofthe torque switch 81. One terminal 122 of the selector relay coil 123 isconnected to the supply line conductor 83 through a normally open manualswitch 124 and is also connected to a movable single contact 125 of theselector relay. The other terminals 126 and 127 of the respective relaycoils are connected to a' second conductor 128 of the power supply line.The remaining fixed contact 129 of the primary relay is connected to thepower supply conductor 128 through the coil of a solenoid 130 whichoperates the plunger pin 57. It should be noted that the selector relayis actuated only when the manual switch 124 is closed. The adjustingplate 88 is held in the desired angular position by a slotted adjustingarm 131 pivotally fastened to the plate 88. A slot 132 in the adjustingarm receives a clamping screw 133 threaded into a stud 134 fastened tothe bracket-arm 13. The relays 111 and 114, manual switch 124 andselector switch 102 may be conveniently located in a small box 135attached to the supporting table 11 within easy reach of the operator.

The construction just described makes it possible for a sewing machineoperator to stop the machine with the needle automatically stopping in apredetermined position, such as the top or the bottom of its stroke,without damaging the sewing machine or the transmitter. Earlier attemptsto obtain the desired result have abruptly stopped the machine in thedesired position by the use of positive brakes such as dental typebrakes or stop pins. This results in a tremendous shock and damage tothe machine parts, since, even at low speeds, a relatively largequantity of energy must be absorbed instantaneously. My constructionpermits the machine to be brought to rest with the needle in the desiredposition without any sudden shock to any of the parts by using anon-positive brake of the friction type which will absorb the kineticenergy of the moving parts relatively gradually.

In the device described, when the sewing machine is operating, thetreadle rod 41 is pulled down by the operators foot pressing on theusual treadle (not shown), which also pulls down the operating lever 40.Since the sleeve 37 is attached to the lever 40, the sleeve is rotatedand, due to the cooperating helical ridges 38 and grooves 39, is shiftedaxially to the left, as viewed in Fig. 5, carrying the shaft 34 and disc33 with it. This action engages the disc 33 with the friction clutchfacing 32 on the flywheel 30 of the constantly running motor 29. Poweris then supplied to the machine through the pulleys 22 and 20 and thebelt 21. The control gear 43 is driven constantly, at a predeterminedreduced speed, through the speed reduction power transmission trainpreviously described, the parts being in the relative positions shown inFig. 5, wherein the control shaft 73 does not contact the switchactuating plunger 82. It should be noted, also, that the friction facing44 does not contact the disc 33. The foot pressure of the operator onthe treadle also causes the treadle to pull the rod 61 downwardly andthrough the spring 60, the control stud 58 is pulled downwardly to thebottom of the curved cam slot 52 as shown in Fig. 12, against thetension of the spring 59. When the control stud 58 is in this positionthe hole 56 in the brake tail 55, carried by the control ring 49, isaligned with the plunger pin 57 and the plunger pin 57 is urged throughthe hole 56 by the spring 56', thus holding the control ring stationary.Under these conditions, the machine operates in a normal manner at anydesired speed.

When it is desired to stop the machine, the operator merely heels thefoot treadle in the usual manner. This forces the control rod 41 to riseand rotates the control lever 40 and sleeve 37 in the opposite directionfrom that required to start the machine. The sleeve 37 now moves to theright, as viewed in Fig. 5, and carries the disc 33 into contact withthe friction facing 44 carried by the control gear 43. Since the tensionhas been released on the rod 61, the spring 59 urges the operating stud58 upwardly, but, the plunger pin 57 remains engaged with the brake tail55 and prevents the control ring 49 from rotating, thus holding thestuds in that portion of the slots 52 which is parallel to the face ofthe disc 33. Thus, the control ring 49 cannot rotate nor can the controlgear move axially. The control gear is held in position with thefriction facing 44 extending slightly to the left of the brake facing47, as viewed in Fig. 5, preventing engagement of the brake.

Assuming the pulley 20 to be rotating clockwise, as viewed from theright end in Fig. l, at high speed, for example 5000 R. P. M. thekinetic energy stored in the moving parts will tend to turn the controlgear 43 clockwise at high speed when the disc 33 and the friction facing44 contact each other. However, the control gear 43 cannot exceed thereduced speed at which it is positively driven by the electric motor 29.The disc 33 is therefore rapidly braked to the speed of the controlgear. If, for example, the control gear rotates at one-eighth of thespeed of the rotor shaft 31, the speed of the pulley 20 will be rapidlyreduced to 625 R. P. M. Since the kinetic energy in the moving partsvaries as the square of the speed, the kinetic energy remaining in themoving machine parts is now only one-sixt'y-fourth of what it was at5000 R. P. M.

Once the machine is slowed to the reduced speed of the control gear 43,power must be supplied to keep the control gear rotating at a constantspeed. The torque spring 78 is strong enough to transmit only the amountof power required to rotate the control gear 43, without any relativerotation occurring between the shafts 68 and 73. The spring 78, however,is not strong enough to transmit the power required to drive the sewingmachine at the reduced speed. Therefore, relative rotation occursbetween the shafts 68 and 73, and the coupling pin 77 moves from itsnormal position shown in Fig. 5 along the helical slot 76. As the pinmoves along the slot, the shaft 73 moves axially to the right as viewedin Fig. 5 to strike the switch plunger 82 and close the torque switch81. This torque-sensing device determines when the machine has reachedthe constant reduced speed and must be power driven to maintain it.

Assuming that the selector switch 102 is closed, with the switch blades107 and 108 connected to the contacts 103 and 104, respectively, theelectrical circuit is now conditioned to stop the machine in a definiteposition of the needle. The machine continues to operate at the reducedspeed until the contact finger 95 reaches the fiat portion 99 of the cam97 at which time the timer contacts 100 close, completing the electricalcircuit through the normally closed selector relay contacts 109 and 115and the primary relay coil 118. When the primary relay coil 118 isenergized, the contacts 120, 129 are closed, completing the circuitthrough the solenoid 130. Upon energizing the solenoid, the plunger pin57 is pulled from the hole in the brake tail 55 allowing the controlstud 58 and ring 49 to rotate under the tension of the spring 59.Rotation of the control ring 49 permits the studs to move into thecurved portion of the slots 52 and thus move the control gear 43 and itsfriction facing 44 to the right, in Fig. 5, until the facing 44 islocated to the right of the brake facing 47, thus releasing the disc 33from the control gear 43 and permitting engagement of the brake. Thedisc 33 is now permitted to move further to the right, in the usualmanner, to engage the brake facing 47 and come to a complete stop. Itshould be noted that once the primary relay 114 operates, a holdingcircuit through the relay coil 113, the torque switch 81 and contacts116, 121 is completed, so that the timer contacts 100 may open withoutdisturbing the sequence of operations.

The entire stopping procedure requires only a fraction of a second fromthe time the operator heels the treadle, until the machine is completelystopped. For example, referring to the graph in Fig. 14, it has beendetermined experimentally that a sewing machine can be brought to acomplete stop from 5000 R. P. M. in approximately of a second,approximately four revolutions, or braked down to /8 of that speed, orabout 625 R. P. M., in slightly less time as indicated by the heavy lineS of the graph. Since the energy to be absorbed in stopping the machinevaries as the square of the speed the stopping distance is reducedproportionately. Therefore, if it requires 4 revolutions or 1440 degreesto stop the machine from 5000 R. P. M., only of that, or about 22 /2, isrequired to stop the machine from 625 R. P. M. For any given machine,these values vary only about 10% and can be predicted with accuracy. Byadjusting the angular position of the plate 88 about the cam 57, theinstant of closing of the timer contacts can be timed to compensate forthe electrical lag in the circuit and for the time required tocompletely stop the machine. Thus, the needle may be automaticallystopped in a predetermined position repeatedly, merely by heeling thesewing machine treadle in the normal manner.

In certain constructions, it is desirable for the ratio between thepulleys and 22 to be 1:1. In this construction, provided that theconnection between the pulleys does not slip, the drive pulley 22, aswell as the pulley 20,

6 will stop in the same position each time the machine is stopped.

Where, as in the device disclosed, a second timer contact assembly 86and a selector switch 102 are provided, the machine may be stopped withthe needle in a second position. When the selector switch 102 ispositioned to connect the switch blades 107, 108 with the contacts 105,106, respectively, the circuit functions as described above, but iscontrolled by the timer contacts 101 instead of contacts 100. Therefore,if the contacts 101 are adjusted to stop the machine when the needle isat the top of its stroke and the contacts are spaced to operate 180later, the machine may be stopped with the needle at the bottom of itsstroke merely by throwing the selector switch 102. The relativepositions of the timer contact assemblies 85 and 86 can be adjusted toany desired relationship, but only one timer contact assembly cancontrol the circuit for each position of the selector switch 102, unlessthe manual switch 124 is closed.

Frequently, it is desirable to stop the machine several times with theneedle in one position, for example at the bottom of its stroke, so thatthe work may be pivoted about the needle, and then to stop the needle ina second position, such as the top of its stroke, so that the work maybe removed. This is accomplished by providing the manual or overrulingswitch 124 connecting one side of the power supply 83 to one end of theselector relay coil 123 and also to the movable contact 125. The sewingmachine is operated, as described above, with the selector switch blade107 connected to the switch contact 103 so that the machine normallystops when the needle is at the bottom of its stroke. When the operatordesires to stop the machine with the needle in the raised position, itis only necessary to close the manual switch 124. When this switch isclosed, the selector relay 123 operates to open the normally closedcontacts 109, and close the normally open contacts 110, 115. Since thecontacts 112, are now closed, a holding circuit is completed through theselector relay coil 123, contacts 112, 125 and the normally closedprimary relay contacts 113, 119 and the manual switch 124 may bereopened Without disturbing the closed circuit. The contacts 109, 115are now open, so that the timer contact assembly 85 no longer controlsthe solenoid operation, and the contacts 110, 115 are now closed toplace contact assembly 86 in control of the circuit. When the timercontacts 101 close, a circuit is completed through the contacts 101 tocause the primary relay 114 and solenoid to operate the plunger pin 57.Operation of the primary relay opens the contacts 113, 119, thusbreaking the holding circuit for the selector relay 111 permitting it toautomatically return to its normal position with contacts 109 and 115closed. When the selector switch 102 is in its other position, theneedle normally stops at the top of the stroke but when the manualswitch 124 is actuated, the timer contacts 100 control the circuit andthe needle will stop at the bottom of its stroke. The manual switch 124overrules the selector-switch 102, so that whichever timer contactassembly is chosen at the selector switch as the controlling contact,actuation of the manual switch places the other contact assembly incontrol.

Once the disc 33 engages the brake facing 47 and the facing 44 carriedby the control gear 43 is free of the disc, the torque spring 78 returnsthe pin 77 and the shaft 73 to their positions shown in Fig. 5 and thetorque switch 81 opens. When the torque switch 81 opens, the primaryrelay 1114 holding circuit through contacts 116, 121 and 109, 115 isbroken, the entire circuit is de-energized and the machine may bestarted again.

In order to start the machine, the operator merely applies pressure tothe treadle of the machine in the normal manner. The disc 33 is movedinto contact with the flywheel friction facing 32, as described above,and the control stud 58 is pulled downwardly against the tension of thespring 59. As the stud 58 moves downwardly,

it follows the contour of the slot 52 and the studs 51, 54 follow theother slots 52, thus forcing the control ring 49 and the control gear 43to move to the left, as viewed in Fig. 5. When the stud 58 reaches thebottom of the straight portion of the slot 52, the plunger pin 57 isagain urged through the hole 56' in the brake tail 55 by the coil spring56. Since the slots 52 permit only limited rotation of the control ring49, the pin 57, under pressure of the spring 56, merely bears on thesurface of the brake tail 55 until it drops in the hole 56. The slots 52are designed so that the control gear 43 carrying the friction facing 44closely follows but does not touch the disc 33 as it moves into contactwith the flywheel facing 32. This eliminates unnecessary lost motionwhen the treadle is heeled. At this point, the machine has returned toits normal operating conditions.

It should be noted that various modifications may be made in the devicewithout departing from the scope of the invention. For example, theshaft 68 may be driven from some constant speed power source other thanthe motor 29. Further, other types of torque sensing devices may be usedto determine when the control gear 43 is receiving power from thecontrol shaft 73 in excess of the amount required to drive only thecontrol gear 43, and the timer may be located in some other positionprovided that a positive driving connection joins it to the actuatingshaft 19.

Referring again to Fig. 14, it should be remembered that variousintervals of time may be required to stop the machine after the operatorheels the treadle. The time interval required to bring the machine fromfull speed to the reduced speed, represented by a point A, may be, forexample, about of a second as shown on the graph, for a given machine.This time may vary widely, depending upon the type of operation beingperformed and the amount of effort the operator applies to the treadle.However, the time required to stop the machine after the torque switch81 is closed may vary over the time required for one revolution of theactuating shaft 19 at the reduced speed. For example, assuming it isdesired to stop the machine with the needle in the raised position, ifthe machine reaches the point A on the graph and the torque switchcloses just after the timer contact 86 has opened, the machine must makeanother revolution before the timer contact 86 will close again tooperate the circuit. At the speeds shown, this requires less thanone-tenth of a second, and the machine will come to rest with the needleraised at the end of about two-tenths of a second after the treadle isheeled as indicated by the curve B. If, however, the reduced speed pointA is reached and the torque switch 81 closes just before the contactassembly 86 closes, the electrical circuit will be immediately energizedupon the closing of the contact assembly 86 and the machine will stopwith the needle raised in a fraction of a second after the torque switchcloses, as indicated by the curve C on the graph. Of course, an infiniterange of stopping time to bring the machine to rest from the reducedspeed is possible depending on the relative positions of the fiat 99 onthe cam 97 and the finger of the controlling contact assembly at thetime the torque switch closes, but in no event will the time be anygreater than that required for one revolution of the actuating shaft 19at the reduced speed plus the time required to stop the machine from thereduced speed. Further, the needle will always stop in the pre-selectedposition.

From the foregoing description, it will be readily apparent that I haveprovided a new and simple mechanism for controlling the position of thesewing needle upon stopping a sewing machine. The mechanism quicklybrings the machine to a complete stop without placing any severe strainon any of the machine parts. The mechanism may be readily adapted foruse with any sewing machine since only the sewing machine balance wheelis replaced by the balance wheel 90 and the timer 87. Further, theinvention may easily be adapted to other types of machines other thansewing machines.

Having thus set forth the nature of the invention, what I claim hereinis:

1. A sewing unit comprising a table; asewing machine mounted on saidtable and having a frame and an actuating shaft rotatably supported insaid frame; a unitary electric clutch-brake motor carried by said tableand having a rotor and a driven shaft, said motor including clutch meansfor operatively connecting said driven shaft to said rotor and brakemeans for restraining rotation of said driven shaft, operator actuatedmeans for actuating said clutch and brake means, power transmissionmeans operatively connecting said driven shaft to said actuating shaft;first switch means operatively connected to said actuating shaft to beopened and closed in synchronism with rotation of said actuating shaft,a solenoid for controlling engagement of said brake, an electricalcircuit operatively connecting said switch means to said solenoid,second switch means operatively connected in said electrical circuit inseries relation with said first switch means, and means operable toclose said second switch means only when said driven shaft is disengagedfrom the rotor.

2. A transmission comprising a primary driving member, a secondarydriving device including a power-flow sensing device, a driven element,an electric contact device operatively connected to said driven elementand having a predetermined control position, connecting means operableto selectively connect said driven element to said member or to saiddriving device, a friction brake for said driven element, a manualcontrol mechanism for operating said connecting means and said brake,and control means connected to said sensing device and to said electriccontact device, operable, when said driving device supplies power tosaid driven element, and said contact device is in said control positionto permit actuation of said brake at a predetermined position of saiddriven element.

3. A power and stop control mechanism comprising a primary drivingmember, a secondary driving device including a power-flow sensing means,a rotatable driven element, connecting means lndependent of said sensingmeans operable to connect said driven element to said primary drivingmember for rotation or to said driving device for rotation at apredetermined constant speed, a brake for gradually stopping said drivenelement, actuating means for said connecting means and said brake, powercontrol means operable to interrupt power flow from said driving deviceto said driven element, and means connected to said sensing means and tosaid driven element and operable to actuate said power control means andto permit actuation of said brake only at said predetermined speed and apredetermined position of said driven element.

4. A power and stop control mechanism comprising a primary drivingmember, a secondary driving device including a power-flow sensing means,a rotatable driven element, an electric contact device operativelyconnected to said driven element, said contact device having a pluralityof predetermined control positions, connecting means operable to connectsaid driven element to said primary driving member for rotation or tosaid driving device for rotation at a predetermined constant speed, abrake for stopping said driven element, actuating means for saidconnecting means and said brake, and means connected to said sensingmeans and to said contact device and operable to permit actuation ofsaid brake only at said predetermined speed and a selected one of saidplurality of predetermined positions of said electric contact device,and selector means operatively connected to said contact device toselect the desired one of the predetermined positions of said drivenelement.

5. A power and stop control mechanism comprising a primary drivingmember, a secondary driving device including a power-flow sensing means,a rotatable driven element, connecting means operable to connect saiddriven element to said primary driving member for rotation or to saiddriving device for rotation at a constant reduced speed, a brake forstopping said driven element, actuating means for said connecting meansand said brake, and means connected to said sensing means and to saiddriven element and operable to permit actuation of said brake only atsaid reduced speed and a selected one of a plurality of predeterminedpositions of said driven element, selector means operatively connectedto said fourth mentioned means to select the desired one of thepredetermined positions of said driven element, and overruling meansoperatively connected to said selector means operable to overruleanother one of the said driven element.

6. A power and stop control mechanism comprising a primary drivingmember, a secondary driving memher, a rotatable driven element, anelectric contact device operatively connected to said driven element andhaving a predetermined control position at a predetermined position ofsaid driven shaft, a brake for stopping said driven element, connectingmeans operable to connect said driven element to said primary drivingmember for rotation or to said secondary member for rotation at aconstant speed, sensing means adapted to determine when said drivenelement is driven at said constant speed, actuating means for saidconnecting means and said brake, and means connected to said sensingmeans and to said electric contact device and operable to permitactuation of said brake only at said constant speed and saidpredetermined position of said driven element.

7. A power and stop control mechanism comprising a driving shaft, arotatable driven element, a clutch operable to connect said shaft andsaid element, an auxiliary driving member, a second clutch operable toconnect said driven element to said driving member, means driving saidmember and including a torque sensing device, a friction brake adaptedto stop rotation of said driven element, actuating means for saidclutches and brake, releasing means operable to disengage said secondclutch, a timer operatively connected to said driven element, meansconnected to said torque sensing device and to said timer operable topermit operation of said releasing means and actuation of said brakeonly when the driven element is in a predetermined position and beingdriven at a predetermined speed. I

8. A power and stop control mechanism comprising a driving shaft, arotatable driven element, a clutch operable to connect said shaft andsaid element, an auxiliary driving member, a second clutch operable toconnect said driven element to said driving member, means driving saidmember and including a torque sensing device, a friction brake adaptedto stop rotation of said driven element, actuating means for saidclutches and brake, releasing means operable to disengage said secondclutch, a timer operatively connected to said driven element having aplurality of contact assemblies operable in diiferent positions of saiddriven element, means connected to said torque sensing device and tosaid timer operable to permit operation of said releasing means andactuation of said brake only when the driven element is in apredetermined position and being driven at a predetermined speed.

9. A power and stop control mechanism comprising a driving shaft, arotatable driven element, a clutch operable to connect said shaft andsaid element, an auxiliary driving member, a second clutch operable toconnect said driven element to said driving member, means driving saidmember and including a torque sensing device, a friction brake adaptedto stop rotation of said driven element, actuating means for saidclutches and brake, releasing means operable to disengage saidsecpredetermined stopping positions of said selector means and select0nd clutch, a timer operatively connected to said driven element havinga plurality of contact assemblies, each assembly being operable in apredetermined position of said driven element, means connected to saidtorque sensing device and to said timer operable to permit operation ofsaid releasing means and actuation of said brake only when said drivenelement is being driven at a predetermined speed and a predeterminedselected one of said contact assemblies operates, and selector means forselecting the predetermined one of said contact assemblies.

10. A power and stop control transmission mechanism comprising a drivingdevice, a normally rotating driven element, a brake adapted gradually tostop said driven element, connecting means operable to connect saiddriven element to said driving device for rotation at a constant reducedspeed, actuating means for said connecting means and said brake, adriving-torque sensing device comprising relatively movable membersincluded in said driving device, and control means connected to saiddriven element and to said torque sensing device, said control meansbeing operable to permit actuation of said brake only when the torque ofsaid driving device exceeds a predetermined amount and when said drivenelement is in a predetermined position.

11. A power and stop control mechanism comprising a primary drivingmember; a secondary driving member; a rotatable driven element; clutchmeans for connecting said driven element to said primary driving member;coupling means for connecting said secondary driving member to saiddriven element; a friction brake adapted to stop rotation of said drivenelement; releasing means normally preventing actuation of said brake andoperable to render said coupling means ineffective and permit actuationof said brake; actuating means for said clutch means, coupling means,brake, and releasing means; power transmission means operativelyconnected to said secondary driving member and including a torqueresponsive device; means connected to said torque responsive device,said releasing means and said driven element operable to permitactuation of said releasing means when said transmission means transmitstorque in excess of a predetermined quantity and when said drivenelement is in a predetermined position.

12. A power and stop control mechanism comprising a primary drivingmember, a secondary driving device including a power-flow sensing means,a rotatable driven element, connecting means operable to connect saiddriven element to said primary driving member for rotation or to saiddriving device for rotation at a constant reduced speed, a brake forstopping said driven element, actuating means for said connecting meansand said brake, and means connected to said sensing means and to saiddriven element and operable to permit actuation of said brake only atsaid reduced speed and a selected one of a plurality of predeterminedpositions of said driven element, selector means operatively connectedto said fourth mentioned means to select the desired one of thepredetermined positions of said driven element, and manually controlledoverruling means operatively connected to said selector means operableto overrule said selector means and select another one of thepredetermined stopping positions of said driven element for one stop ofsaid driven element.

13. A sewing mechanism and a driving device for said sewingmechanismcomprising a primary rotating shaft adapted to be operatively connectedfor driving said sewing mechanism; an auxiliary member rotated duringthe operation of and at a speed reduced from said primary rotating shaftfor driving said sewing mechanism; electric motor means driving saidshaft and said member; operator-controlled means for at will selectivelycontrolling the effective operation of said primary shaft and auxiliarymember to drive said sewing mechanism; brake means associated with saidauxiliary member means for stopping said sewing mechanism; andelectrical control means operatively connected to said brake means andincluding a timer contact operatively connected to said sewing mechanismand adapted to determine one stopping position of said sewing mechanism,a second timer contact operatively connected to said sewing mechanismand adapted to determine a second stopping position of said sewingmechanism, selector means connected to said contacts for selecting oneof the stopping positions, and means to overrule said selector means andselect the other of said stopping positions.

14. A sewing unit comprising a supporting table, a sewing machinecarried by said table and having a needlecarrier and a rotatable mainshaft operatively connected to said needle-carrier, a unitary electricpower transmitter having a rotor and a rotatable driven shaft, a mainclutch for connecting said driven shaft to said rotor, auxiliary drivingmeans for rotating said driven shaft, a second clutch for connectingsaid driven shaft to said auxiliary driving means, brake means forgradually stopping said driven shaft, operator actuated means forcontrolling engagement and disengagement of said clutches and brakemeans, power transmission means operatively connecting said driven shaftto said rotatable main shaft, electrical control means for controllingengagement of said brake means, said electrical control means includinga first switch device adapted to be opened and closed in synchronismwith said rotatable main shaft, and a second switch device adapted to beclosed when said main clutch is disengaged.

15. A sewing unit comprising a supporting table, a sewing machinecarried by said table and having a needleca-rrier and a rotatable meanshaft operatively connected to said needle-carrier, a unitary electricclutch-brake power transmitter carried by said table and having a rotorand a driven shaft, said transmitter including a clutch for connectingsaid driven shaft to said rotor and brake means for stopping said drivenshaft, power transmission means operatively connecting said driven shaftto said rotatable main shaft, operator actuated means for engaging anddisengaging said clutch and said brake means, electrical control meansfor controlling the stopping of said driven shaft by said brake means,said control means including electrical contact means adapted to beopened and closed in synchronism with rotation of said rotatable shaft,and a switch included in said control means for rendering said controlmeans ineffective when said clutch is engaged.

16. A sewing unit comprising a table, a sewing machine carried by saidtable, said sewing machine having a needle-carrier and a rotatable shaftoperatively connected to said needle-carrier, a unitary electric powerclutch-brake transmitter carried by said table, said transmitterincluding a rotor and a driven shaft, a clutch for operativelyconnecting said driven shaft to said rotor, brake means for stoppingsaid driven shaft, operator actuated means for controlling engagementand disengagement of said clutch and brake means, an electrical controlsystem operatively connected to said sewing machine and said transmitterfor permitting said brake to stop said rotatable shaft only when saidrotatable shaft is in a prescribed position, said control systemincluding a solenoid for controlling engagement of said brake means andswitch means actuated by said operator actuated means for energizing anddisabling said electrical control system, and power transmission meansoperatively connecting said driven shaft to said rotatable shaft.

17. In a control mechanism for a sewing machine, in combination, maindriving means with energizing means therefor, a rotary part rotatablewith and driven by the main driving means, braking means journaled forrotational movement with the rotary part and adapted to cooperate withthe rotary part gradually to retard the machine, slow speed drivingmeans operatively connected with the braking means to drive the brakingmeans at a 12 speed slower than the speed of the main driving means, anelectrical circuit for controlling the operation of the low speeddriving means, operator-influenced means for preparing the electricalcircuit for controlling the low speed driving means and rendering themain driving means ineffective to drive the rotary part, means movablesynchronously with the machine, and the electrical circuit includingmeans cooperative with the synchronously movable means and effectiveonly when the circuit has been prepared and the rotary part has beendriven by said low speed driving means to a predetermined angularposition to render the slow speed driving means ineffective to rotatethe rotary part.

18. In a control mechanism for a sewing machine having a rotatable partwith a predetermined angular home position, a main high speed drivingmember for normally driving the part at high speed, and meanssequentially rendering the main driving member ineffective to drive therotary part, retard the rotary part gradually, drive the part at a speedsubstantially less than that of the main driving member and finallystopping the rotary part in its predetermined angular home position;said means including braking means journaled for rotational movementwith the rotary part and adapted gradually to retard the rotary partwhen initially connected therewith, a slow speed auxiliary drivingmember operatively connected with the braking member to drive thebraking member at a predetermined low speed, an electrical circuit forcontrolling the operation of the auxiliary driving member,operator-influenced means for rendering the main driving memberineffective to drive the rotary part and for preparing the electricalcircuit for controlling the auxiliary driving member, means movablesynchronously with the rotary part, and the electrical circuit includingmeans cooperative with the synchronously movable means and effectiveonly when the circuit has been prepared and the rotary part has beendriven by the auxiliary drive member to a predetermined angular homeposition to render the auxiliary driving member ineffective to rotatethe rotary part.

19. In a control mechanism for a sewing machine, in combination, maindriving means with energizing means therefor, a rotary part rotatablewith and driven by the main driving means, first braking means journaledfor rotational movement with the rotary part and adapted to cooperatewith the rotary part to retard the machine, slow speed driving meansoperatively connected with the first braking means to drive the brakingmeans at a speed slower than the speed of the main driving means, anelectrical circuit for controlling the operation of the low speeddriving means, operator-influenced means for preparing the electricalcircuit for controlling the low speed driving means and rendering themain driving means ineffective to drive the rotary part, second brakingmeans, means movable synchronously with the machine, and the electricalcircuit including means cooperative with the synchronously movable meansand effective only when the circuit has been prepared and the rotarypart is driven by the first braking means at a predetermined rotationalspeed to render the slow speed driving means ineffective to rotate therotary part and to render the second braking means effective to stop therotary part in a predetermined angular position.

20. A power drive mechanism which comprises a frame, an electric motorhaving a rotor shaft journaled in the frame, a driven power take-01fshaft journaled in said frame, a friction brake journaled in the framefor rotational movement, operator-influenced means connected with theframe to connect the driven power takeoff shaft operatively with eitherthe rotor shaft or the friction brake, means carried by the frame forrotating the friction brake at a speed substantially less than that ofthe rotor shaft, an electrical circuit for controlling the operation ofthe friction brake, means included in the electrical circuit which whenactuated is effective to 13 render the friction brake ineffective torotate the power take-off shaft.

21. A power drive mechanism as claimed in claim 20 and wherein the rotorshaft, the driven power take-olf shaft and the friction brake are alljournaled within said frame about a common rotary axis.

22. A power drive mechanism as claimed in claim 20 and wherein the powertake-off shaft is shiftable lengthwise of its rotary axis for operativeengagement with the rotor shaft and the friction brake.

23. A power drive mechanism as claimed in claim 20 and wherein thefriction brake is driven by the electric motor.

24. A mechanism for driving a sewing machine having a rotary shaft,comprising, a unitary electric clutch-brake power transmitter having arotor :and a driven shaft, said transmitter including :a clutch forconnecting said driven shaft to said rotor and brake means for stoppingsaid driven shaft, power transmission means adapted for operativelyconnecting said driven shaft to said sewing machine rotary shaft,operator actuated means for engaging and disengaging said clutch andsaid brake means, electrical control means for controlling the stoppingof said driven shaft by said brake means in a selective one of aplurality of predetermined angular positions, said control meansincluding electrical contact means adapted to be opened and closed insynchronism with rotation of said sewing machine rotary shaft, a switchincluded in said control means for rendering said control meansineffective when said clutch is engaged, and selector means operativelyconnected to said contact device to select the desired one of thepredetermined positions of said driven shaft.

25. A mechanism as claimed in claim 24 and including overruling meansoperatively connected to said selector means operable to overrule saidselector means and select another one of the predetermined stoppingpositions of said driven shaft.

26. A mechanism for driving a sewing machine having a rotary shaft,comprising, a unitary electric power transmit-ter having a rotor and arotatable driven shaft, a main clutch for connecting said driven shaftto said rotor, auxiliary driving means continuously driven from and at aspeed substantially less than that of said rotor, a second clutch forconnecting said driven shaft to said auxiliary driving means, brakemeans for gradually stopping said driven shaft, operator actuated meansfor controlling engagement and disengagement of said clutches and brakemeans, power transmission means .adapted for operatively connecting saiddriven shaft to said sewing machine rotary shaft, electrical controlmeans for controlling engagement of said brake means, said electricalcontrol means including a first switch device adapted to be opened andclosed in synchronism with said sewing machine rotary shaft, and asecond switch device adapted to be closed when said main clutch isdisengaged.

27. In a control mechanism for a sewing machine in combination, maindriving means with energizing means therefor, a rotary part rotatablewith and driven by the main driving means, braking means journaled forrotational movement with the rotary part and adapted to cooperate withthe rotary part gradually to retard the machine, slow speed drivingmeans operatively connected with the braking means to drive the brakingmeans at a speed slower than the speed of the main driving means, anelectrical circuit for controlling the operation of the low speeddriving means, operator-influenced means for preparing the electricalcircuit for controlling the low speed driving means and rendering themain driving means ineffective to drive the rotary part, means movablesynchronously with the machine, the electrical circuit including meanscooperative with the synchronously movable means and effective when thecircuit has been prepared and the rotary part has been driven by saidlow speed driving means to a selected one of a plurality ofpredetermined angular positions to render the slow speed driving meansinelfective to rotate the rotary part, and operator-influenced means forselecting that angular position at which the slow speed driving means isto be rendered ineffective to rotate the rotary part.

28. In a control mechanism as claimed in claim 27 and includingoverruling means operatively connected with the last mentionedoperator-influenced means operable to overrule such means and selectanother one of the predetermined stopping positions of said drivenshaft.

29. In a control mechanism for a sewing machine having a rotatable partwith a plurality of predetermined angular home positions, a main highspeed driving member for normally driving the part at high speed; meanssequentially rendering the main driving member ineffective to drive therotary part, retard the rotary part gradually, drive the part at a speedsubstantially less than that of the main driving member and finallystopping the rotary part in a selective one of its predetermined angularhome positions; said means including braking means journaled forrotational movement with the rotary part and adapted gradually to retardthe rotary part when initially connected therewith, a slow speedauxiliary driving member operatively connected with the braking memberto drive the braking member at a predetermined low speed, an electricalcircuit for controlling the operation of the auxiliary driving member,operator-influenced means for rendering the main driving memberineffective to drive the rotary part and for preparing the electricalcircuit for controlling the auxiliary driving member, means movablesynchronously with the rotary part, and the electrical circuit includingmeans cooperative with the synchronously movable means and effectiveonly when the circuit has been prepared and the rotary part has beendriven by the auxiliary drive member to a predetermined angular homeposition to render the auxiliary driving member ineffective to rotatethe rotary shaft; and operator-influenced means for selecting thatangular home position at which the auxiliary drive member is to berendered ineffective to rotate the rotary part.

30. A power mechanism for driving a sewing machine having a rotaryshaft, comprising a frame, an electric motor having a rotor shaftjournaled in the frame, a driven power take-off shaft journaled in theframe, a friction brake journaled in the frame for rotational movement,power transmission means adapted for operatively connecting the powertakeoff shaft with the sewing machine rotary shaft, operator-influencedmeans mounted on the frame to connect the power take-01f shaftoperatively with either the rotor shaft or the friction brake, meanscarried by the frame for rotating the friction brake at a speedsubstantially less than that of the rotor shaft, an electrical circuitfor controlling the operation of the friction brake, means included inthe electrical circuit which when actuated is effective to render thefriction brake ineffective to rotate the power take-off shaft.

31. A power mechanism as claimed in claim 30 and wherein the rotorshaft, the driven power take-off shaft and the friction brake are :alljournaled within the frame about a common rotary axis, and wherein thepower takeoff shaft is shiftable lengthwise of the common rotary .axisfor operative engagement with the rotor shaft and the friction brake.

32. In control mechanism for a sewing machine, in combination: a brakeelement for retarding the movement of the machine, a rotary partrotatable with the machine and adapted to be engaged by said brakeelement, means supporting the brake element for rotational movementtogether with said rotating part of the machine, a slow speed drivingmeans, means connecting said driving means with said brake element andpermitting .a limited angular movement of the brake element with respectto the driving means, an interrupter member movable with the machine,electrical means for controlling the operation of the slow speed drivingmeans and the brake element, and a control member for said electricalmeans adapted to be moved, upon the relative limited angular movement ofthe brake element, by said interrupter member thereby to disconnect saidslow speed driving means.

References Cited in the file of this patent UNITED STATES PATENTS Re.15,125 Lindquist et a1.v June 14, 1921 UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION August 19, 1958 Patent No. 2,847,956

Arthur No Hale It is hereby certified that error appears in the printedspecification of the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below.

Column ll, line 33, claim 15, for "mean" read main Signed and sealedthis 28th day of October 1958.,

(SEAL) Attest:

KARL Hm .AXLINE ROBERT C. WATSON Commissioner of Patents AttestingOfficer

